US 12,072,477 B2
Variable magnification optical system, optical device, and method for manufacturing variable magnification optical system
Tomoyuki Sashima, Tokyo (JP); and Akihiko Obama, Tokyo (JP)
Assigned to Nikon Corporation, Tokyo (JP)
Filed by Nikon Corporation, Tokyo (JP)
Filed on Jun. 12, 2023, as Appl. No. 18/208,677.
Application 18/208,677 is a division of application No. 17/701,670, filed on Mar. 23, 2022, granted, now 11,714,268.
Application 17/701,670 is a division of application No. 16/037,803, filed on Jul. 17, 2018, granted, now 11,294,155, issued on Apr. 5, 2022.
Application 16/037,803 is a division of application No. 14/700,703, filed on Apr. 30, 2015, granted, now 10,185,130, issued on Jan. 22, 2019.
Application 14/700,703 is a continuation of application No. PCT/JP2013/079242, filed on Oct. 29, 2013.
Claims priority of application No. 2013-004650 (JP), filed on Jan. 15, 2013; application No. 2013-004651 (JP), filed on Jan. 15, 2013; and application No. 2013-004652 (JP), filed on Jan. 15, 2013.
Prior Publication US 2023/0324657 A1, Oct. 12, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G02B 15/14 (2006.01); G02B 27/64 (2006.01)
CPC G02B 15/143105 (2019.08) [G02B 27/646 (2013.01); Y10T 29/49826 (2015.01)] 12 Claims
OG exemplary drawing
 
1. A variable magnification optical system comprising, in order from an object side, a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; a fourth lens group having negative refractive power and a fifth lens group having positive refractive power;
upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group, a distance between the second lens group and the third lens group, a distance between the third lens group and the fourth lens group and a distance between the fourth lens group and the fifth lens group being varied, and the first lens group, the third lens group and the fourth lens group being moved to the object side; and
the following conditional expression being satisfied:
0.170<(−f4)/f5<0.400
where f4 denotes a focal length of the fourth lens group and f5 denotes a focal length of the fifth lens group.